Implementasi Algoritma Caesar Chiper dan Rail Fence untuk Peningkatan Keamanan Teks Berbasis Client Server

SMK Negeri 3 Bengkulu City is one of the vocational schools in Bengkulu City. The school has a major in Computer and Network Engineering (TKJ). Students will be taught about basic knowledge in computers, network infrastructure, network security and others. Cryptography is part of a security system, where cryptography is the science and art of keeping messages secure. Increased security in the form of an encryption process that is carried out through 2 stages before getting the encryption results, namely encryption using the Caesar Cipher Algorithm and then being encrypted again using the Rail Fence Algorithm. To assist the text security system at SMK Negeri 3 Bengkulu City, a client server-based application was built using the Visual Basic .Net programming language with SQL Server database. In its application, one laptop will be used as a database server, so that the results of inputting text that will be sent to the recipient are automatically stored on the server. While the client only accesses the form of sending and receiving messages through the application that has been provided. If you enter an incorrect or incorrect key, then the plaintext cannot be changed to its original form so that the text message cannot be read